Zenith motorcycles were manufactured from 1904 until 1950, in a variety of factories in or around London. From the early days proprietary engines were used, such as Fafnir, Precision, JAP, Bradshaw and Villiers. The driving force behind Zenith was Chief Engineer, and company owner, Frederick Barnes, who was responsible for the famous 'Gradua' gear. Although the expensive Gradua system gave way to a more conventional Sturmey-Archer countershaft gearbox in the 1920s, Zenith continued to pursue its racing and record breaking activities with enthusiasm. Fred Barnes himself enjoyed considerable success at Brooklands, where in 1922 Zenith rider Bert Le Vack became the first man to lap at over 100mph on a motorcycle in the rain. In 1928 a Zenith-JAP ridden by Oliver Baldwin established a world motorcycle speed record of 124.62mph at Arpajon in France, while Joe Wright later raised the record to 150.736mph using his supercharged Zenith-JAP 'reserve bike'. Despite adding a Villiers-powered economy model to the range, Zenith failed to weather the financial storms of the 1930s; after a succession of closures and changes of ownership it re-emerged after WW2 with a solitary model: a 750cc JAP-powered sidevalve v-twin, which lasted only a few more years.
The largest model of the Zenith range, this JAP-engined CP is believed to have been destined for exhibition at the 1939 Earls Court Motor Cycle Show, an event cancelled following the outbreak of war. A letter written by a former owner, Mr Alan J Dunn, (Zenith Registrar and Founder and Honorary Secretary of the Brooklands Section), states that he was told by the preceding owner, firmly and at length, that this machine was built for exhibition at the 1939 show. We are advised that its sidevalve JAP engine (dating from 1933) was intended for a Brough Superior '11-50' but was returned and fitted at great cost with bronze cylinder heads. The machine was first registered on 1st October 1943, a receipt documenting it as a 1939 machine previously used 'for test and experimental use only'. During the war years, certain materials were hard to come by and chroming of parts became a rarity, hence the wheel rims are painted black. The Zenith was fitted with Brampton front forks and a sidecar, as seen in a photograph taken during the 1960s. The VMCC's Register of Machines 3rd edition lists this machine as the only Zenith 1100 sidevalve (copy extract on file). The machine is offered with a 1939 Zenith brochure (copy) and a V5C registration document.